Nitrogen-containing oil-soluble polymeric detergents



United States Patent Int. or. cost 19/00 US. Cl. 260-861 3 Claims ABSTRACT OF THE DISCLOSURE Oil additives comprising oil-soluble high molecular weight copolymers of a polymerizable heterocyclic nitrogen-containing compounds and esters of lower alkyl acrylic acids and an OX0 alcohol of a highly branched-chain olefinic polymer in the molecular weight range of from 800 to 10,000.

This patent application is a division of copending patent application Ser. No. 340,520, filed Jan. 27, 1964, and now Patent No. 3,278,437.

This invention relates to a new and novel class of nonash forming polymeric detergents and corrosion and wear inhibitors capable of imparting these desired properties to base lubricants.

It has now been discovered that improved detergency, viscosity index, as Well as corrosion and wear inhibitors can be produced by copolymerization of and 6-membered heterocyclic nitrogen-containing compounds such as vinylpyridine or vinylpyrrolidone and an ester of an acrylic acid and high molecular weight alcohols derived from olefinic polymers in the molecular weight range of from 800 to 10,000, preferably between 1,200 and 5,000 molecular weight. Highly branched olefinic polymers are preferred although straight-chain, or mixtures of straightchain and branched materials may be used.

The alcohols in the molecular weight range indicated can be derived from polyolefins, e.g., polyisobutylene, polypropylene, polyethylene, polyisoamylene, or various petroleum stocks via known reactions such as the OX0 process, or be made in the final step of the polymerization process e.g., via the Augbau process or via a telomerization process. The conversion of the olefinic polymers to the alcohols by the OX0 process can be accomplished by any suitable means such as described in US. Patents 2,644,844, 2,811,567, 2,834,815, and 3,007,973. A preferred method for forming the OX0 alcohols (A) is obtained by reacting unsaturated polyisobutylene (mol wt. 1,200-5,000) with hydrogen and carbon monoxide in the presence of cobalt carbonyl-tributyl phosphine catalyst at between 150-200" C. and 1,500-3,000 psi. for about 100150 hours. Any aldehydes present are converted to the alcohols by reduction in the presence of lithium aluminum hydride in an oxygen-containing solvent such as tetrahydrofuran. The alcohol is recovered from the solvent, washed and dried.

The esters of an acrylic acid and the highly branched chain high molecular weight OX0 alcohol such as illustrated by Example A are obtained by transesterification of C alkyl acrylates such as methyl acrylate or methyl methacrylate and the desired Oxo alcohol such as alcohol (A). Esters useful in forming copolymers of the present invention can be represented by the formula mice wherein R is hydrogen or a C alkyl or aryl radical, preferably a CH radical and R is the residue of the Oxo alcohol derived from highly branched chain olefinic polymer in the molecular weight range of from 800 to 10,000, preferably between 1,200 and 5,000.

Esters of the above type can be formed by the method described, namely, by reacting acids or their C alkyl acrylate esters of column (X) with the OX0 alcohols of column (Y), both columns being listed below.

Column (X):

(1) Acrylic acid (2) Methacrylic acid (3) ot-Ethacrylic acid (4) u-Phenyl acrylic acid (5) Methyl acrylate (6) Methyl methacrylate (7) Methyl a-ethacrylate (8) Methyl arphenylacrylate (9) Ethyl methacrylate (10) Butyl methacrylate Column (Y) (OX0 alcohols derived from unsaturated polymers):

(1 Polyisobutylene (M.W. 800) (2 Polyisobutylene (M.W. 1200) (3 Polyisobutylene (M.W. 5000) (4 Polyisobutylene (M.W. 10,000) (5 Polyisoamylene (M.W. 1,500) (6 Polypropylene (M.W. 1000) (7 Polypropylene-isobutylene (M.W. 2000) (8 Polyolefin petroleum feed (M.W. 2500) (9 Polyethylene-polyisobutylene (M.W. 1500) (10 Polyisobutylene-polyisoamylene (M.W. 2000) (11 Copolyethylene propylene (M.W. 1000) (12 Polyethylene a-methylstyrene (M.W. 1200) (13 P-Oly-S-methylbutene (M.W. 1200) Preferred esters are those formed by reacting: B=(5) and (2 C=(5) and (3 D=(6) and (21); E=(6) and (3 F=(6) and 9 G=(6) and (13 H=(7) and (2 I=(8) and (5 i=(2) and (2 K=(6) and 1) Although mixtures of esters of the present invention are not required to form multifunctional copolymeric additives of the present invention as are required with related prior art copolymers referred to above, they may be used. Thus, with esters used to form the novel copolymers of the present invention only one ester such as represented by (B) or (C) or the like is required, and such copolymers not only impart oil solubility, but improve the viscosity index of all the oil, but also unexpectedly increases the detergency and corrosion inhibiting properties of the copolymer. Thus, copolymers of the present invention obviate manufacturing and reaction problems presented by the prior art, but also form superior products.

The nitrogen-containing monomers used to form the copolymers of the present invention can be represented by the formula R(I3=(|3H R1 R2 (H) where R and R can be hydrogen and/or alkyl radicals and R is a 5- or 6-membered heterocyclic nitrogen-containing ring and which contains one or more substituent hydrocarbon group(s). In the Formula II the vinyl radical can be attached to the nitrogen or to a carbon atom in the radical R. Examples of such vinyl derivatives include 2-vinylpyridine, 4-vinylpyridine, 2-methyl-5- vinylpyridine, 2-ethyl-5-vinylpyridine, 4-methyl-5-vinylpyridine, N-vinylpyrrolidone, 4-vinylpyrrolidone, and the like.

The copolymers of the present invention are made by 3 4 polymerizing a nitrogen-containing monomer of Formula where D is the ester as defined, X is 2-vinylpyridine and II with an ester of Formula I in the mol ratio of 1:10 to Y is a-methylstyrene. 10:1, preferably in the mol ratio of 1:3 to 4:1 respectively The random and block polymers according to the inunder polmerizing conditions as described in US. Patent vention are suitable for use as additives for lubricants 2,889,282 or 2,957,854 to obtain randomly distributed of different nature. In the first place, mineral lubricating monomeric units in the copolymer and the copolymer 5 oils of various viscosities may be mentioned. Synthetic varies in molecular weight from 5x10 to 3 l0 as lubricating oils are also suitable, however, as well as determined by the light scattering method and has a lubricating oils containing fatty oils. The products can nitrogen content of from 0.20 to 3.5% wt. nitrogen in also be incorporated in lubricating greases.

the end product. Thus, following the procedure of the 10 The polymers can be added to the lubricant as proabove-mentioned patents the following copolymers of the duced or else as a concentrate obtained by mixing them present invention were prepared: with a little of a lubricating oil.

I II III IV V VI VII VIII IX X 2-methyl5-vinylpyridine, percent 7. 5 15.2 14. D

w 2-vinylpyridlne 5 RC=CH (II) 4-vinylpyridine N-vinylpyrrolidone R R 5-methyl-N-vinylpyrrolidone..

B=(5)+(.3Z1) percent wt Percent wt. Nitrogen in end product (copolymer).

Ratio of (I):(II) in end product.-. 1.93:1 1:287 1:231 1.81 1. 9:1 2:1 1:1. 7

M01 wt. (Light Scattering) 3X10 7. 5X10 2X10 6X10 4. 5X10 6X10 6. 5X10 Another embodiment of the present invention is to The polymers of this invention can be used in lubricatform block copolymers. These can be prepared by polyming oils in amounts ranging from about 0.1% to about erizing one of the monomers such as (I) or (II) to the 5% by weight, preferably from about 0.5% to about 3% desired degree of polymerization and, subsequently, iniby weight.

tiating, with the living homopolymer obtained, the polym- When desired, additional improvements with respect to erization of the other type of monomer. Another possioxidation stability and scuffing inhibition can be imparted bility is a method of preparation according to which to the oil compositions containing the polymer of this homopolymers of Formula I and Formula II are coupled to invention by incorporating small amounts (0.0l%-2%, each other. If then both the homopolymers have two repreferably 0.l%l%) of phenolic antioxidants such as active terminal groups, a block polymer with a variable alkylphenols, e.g., 2,6-ditertbutyl-4-methylphenol or p,p'- number of blocks is formed; if one of the homopolymers 40 methylene bisphenols such as 4,4'-methylenebis(2,6-dihas two reactive terminal groups and the other only tertbutylphenol) or arylamines such as phenyl-alphaone, a block polymer consisting of three blocks is formed. naphthylamine. Antiscutfing agents include organic phos- Preparation of the block polymers by means of anionic phites, phosphates, phosphonates and their thio-derivapolymerization is preferred. An alkali metal or an alkali tives, such as tri(C alkyl phosphites), or phosphates, metal compound of an hydrocarbon is then used as the e.g., tributyl, octyl, lauryl, stearyl, cyclohexyl, benzyl,

initiator. If such an initiator and one of the monomers cresyl, phenol phosphites or phosphates, as well as their are combined, a polymer is formed of which one or either thio-derivatives, P S -terpene reaction products, e.g., of the terminal groups is a carbanion, or, depending on P S pine oil reaction products, e.g., P S -pine oil reacthe solvent applied, a carbon-metal bond. tion products and alkali metal salts thereof such as potas- Suitable initiators for the anionic polymerization are sium salt of a P S -terpene reaction product, phosphates the metals sodium, potassium, lithium, rubidium, cesium such as dibutyl trichloromethanephosphonate, dibutyl and their hydrocarbon compounds, for instance, sodium monochloromethanephosphonate, and the like. The trinaphthalene, butyl lithium, Naflalphamethyl styrene) phenyl, tricresyl and tristearyl ortho-phosphates or potasbenzyl sodium and phenyl isopropyl potassium. sium salt of P S -terpene reaction product are preferred. The solvent used can be tetrahydrofuran, benzene, hex- Lubricating oils for additives of this invention can be ane, dimethoxyethane and others. any natural or synthetic material having lubricating prop- The following example illustrates the method of preerties. Thus, the base may be a hydrocarbon oil of wide paring block copolymers of the present invention. Viscosity range, 100 SUS at IO 150 SUS at 210 F. The hydrocarbon oils may be blended synthetic EXAMPLE XI lubricants such as polymerized olefins, organic esters of H poly-basic organic and inorganic acids, e.g., di-Z-ethyl- To tetrayhdrofuran containing as the initiator sodium h l Sebacate; l lk l ili polymers, 90g dimeth- Oljmethyl styfenefetfamef was added 10% 0f Y PY yl silicone polymer, and the like. If desired, the synthetic dlne and the mixture p y Stirred and p at lubricants may be used as the sole base lubricant.

y T0 y PY )7 Polymers of this invention can be also used in fuels, methylstyren h (2-v1ny1pyr1 1 ha polymer formed e.g., gasoline, fuel oils, lubricating oils, greases, asphalts was added 90% 0f ester D=(6)|(1) and addition 801- and oil-water emulsions,

vent tetrahydrofuran added. The reaction mixture was Th following formulated compositions were tested in stirred and at the end of about an hour terminated by the manner d s ribed below:

addition of lsopropanol. The reaction mixture was poured Composition A=( mineral lubri atin oil +1.5% eointo a large volume of methanol from which the precipipolymer 1),

tated polymer was recovered by filtration. The block co- Composition B:(mineral lubricating oil|-l.5%copolypolymer had a nitrogen content of 0.9-1.2% wt. and a mer III),

structure:

Composition C= (Composition A+O.75% bis(3,5-ditertbutyl-4-hydroxyphenyl)methane,

1 Mineral lubricating oil: SAE 30.

Composition D= (Composition C+0.8% tricresyl phosphate-F0.04% dicresyl phosphate), Composition E=(Composition B+0.5% bis(3,5-ditertbutyl-4-hydroxyphenyl)methane,

Compositions of this invention were tested for their detergency and dispersancy properties by adding 0.02% carbon black to a test composition and suspending into said test oil at both ambient temperature and at 110 C. a strip of filter paper of set dimensions and observing the height and intensity of the carbon band formed on the filter paper. Compositions A, B, C, D, and E exhibited at both temperatures detergency effectiveness of 3 to 4 times that of compositions containing convention copolymers as described in US Patent 2,889,282, such as compositions:

Compositions XX=mineral oil+2% 2-methyl-5-vinylpyridine/lauryl methacrylate/stearyl methacrylate Compositions YY=mineral oil-l-(same terpolymer of maleic anhydride/ vinyl acetate/C alkyl fumarate Also in engine tests such as the LS-3 Cadillac engine test modified as follows: 100 hours, 400 repeating cycles of 15 minutes each, comprising 1 minute at 90 F. jacket temperature, minutes at 135 F. jacket temperature, 2500 rpm. and 4 minutes at 190 F. jacket temperature at 3200 rpm; operated on high sulfur fuel, Compositions A, C, D and E passed the 100 hour test and prevented oil ring-plugging, left oil rings clean and the engine was in excellent condition whereas Compositions XX and YY failed within 50-75 hours, especially with respect to ringplugging.

Other additives may also be incorporated into the lubricating composition according to the invention, for example, antiscuffing agents; antiforming agents, e.g., silicone polymers; viscosity index improvers, pour point depressants, extreme pressure additive such as, dibenzyl disulfide, rust inhibitors, such as sorbitan monooleate or butyl stearate; oiliness agents, which as acidless tallow, oleic acid and the like.

We claim as our invention:

1. An oil-soluble high molecular weight copolymer of a polymerizable heterocyclic nitrogen-containing compound selected from the group consisting of N-vinylpyrrolidone and C-vinylpyridine and an ester of a lower alkyl acrylic acid and an Oxo alcohol of a highly branchedchain olefinic polymer in the molecular weight range of from 800 to 10,000 in the mole ratio of 1:10 to 10:1, respectively, the molecular weight of the copolymer ranging from 5x10 to 3 X10 2. An oil-soluble copolymer of Z-methyl-S-vinylpyridine and an ester of methacrylic acid and an OX0 alcohol derived from polyisobutylene in the molecular weight range of from 1200 to 5000 in the mole ratio of 1:3 to 4:1, respectively, said copolymer having a molecular weight range of from 5x10 to 3 X10 3. An oil-soluble copolymer of N-vinylpyrrolidone and an ester of methacrylic acid and an OX0 alcohol derived from polyisobutylene in the molecular weight range of from 1200 to 5000 in the mole ratio of 1:3 to 4: 1, respectively, said copolymer having a molecular weight range of from 5 10 to 3 X10 References Cited UNITED STATES PATENTS 3,142,664 7/1964 Bauer. 3,153,640 10/1964 Barnum et al. 3,232,912 2/1966 Munday et a1. 3,287,283 11/1966 Metro. 3,380,928 4/ 1968 Hughes et a1.

HARRY WONG, JR., Primary Examiner US. Cl. X.R. 

